Many refrigerant circuits in, for example, air conditioners use refrigerant passage change-over valves for switching passages of refrigerant in order to switch operation between cooling and heating, for example. One of such refrigerant passage change-over valves is used to control a communication state among ports in a hermetic case by rotating a movable valve body rotatably attached to a hermetic case by a motor to switch the positional relationship among the ports and grooves formed on the movable valve body (see, for example, Patent Document 1).